Australian researchers at the Center for Human Psychopharmacology measuring brain waves of volunteers found the EGCG in tea has a calming effect producing “relaxed alertness.”
Lead researcher Andrew Scholey sought to discover whether the flavonoid epigallocatechin gallate (EGCG) modulates brain activity and self-reported mood in a double-blind, placebo controlled crossover study.
Participants completed baseline assessments of cognitive and cardiovascular functioning, mood and a resting state electroencephalogram (EEG) before and two hours after receiving 300 mg EGCG or matched placebo, according to Scholey.
He writes that “EGCG administration was associated with a significant overall increase in alpha, beta and theta activity, also reflected in overall EEG activity, more dominant in midline frontal and central regions, specifically in the frontal gyrus and medial frontal gyrus. In comparison to placebo the EGCG treatment also increased self-rated calmness and reduced self rated stress. “
“This is in keeping with the widespread consumption of green tea for its purported relaxing/refreshing properties,” he concludes.
EGCG is one of the key flavonoid phytonutrients found in the Camellia sinensis, the plant from which green, white, black, and oolong teas are made, writes Dr. Michael Greger who has written about similar findings with the active ingredient L-Theanine.
Using an electroencephalogram, researchers were able to anatomically match changes in brain wave activity to the feelings of a relaxed alertness that participants reported when consuming the tea phytonutrients, compared to a double-blinded placebo, he writes.
In a report on his website, Care2Make a Difference (www.Care2.com) Dr. Greger an author, physician and founder of the American College of Lifestyle Medicine, describes in a video how the introduction of L-theanine (50 mg) has a similar pronounced effecting on brain wave activity (pictured here).
The phytonutrient theanine “offers another neurological basis for humanity’s love affair with tea,” writes Dr. Greger. “Relaxed and aware is where we want to be. How do we get there? Drink tea,” he says.
There are benefits to tea drinking beyond just making us feel good, such as extending our lifespan.
This may explain the so-called Asian Paradox, why people living in Asia have lower heart disease and lung cancer rates despite their high level of smoking.
“How many cups a day of green tea are associated with increased longevity, though?” he asks.
“Five.”
Sources: Appetite, Acute Neurocognitive Effects of Epigallocatechin Gallate